In blood pressure measurement devices, it is customary to use a Velcro closure to tighten the cuff around a limb, in particular an upper arm or a wrist. To measure the arterial blood pressure, a pressure bladder provided in the cuff is pumped up until an artery is constricted. The fluid is then slowly released from the pressure bladder, whereupon the pulse causes an oscillation of the fluid pressure in the pressure bladder, and this can be used to determine, for example, the systolic and the diastolic blood pressure. However, variations or errors in the measurement values occur if the cuff is placed too tightly or too loosely around the limb. This cannot really be avoided, however, when applying the cuff by hand.
It has therefore already been proposed to tighten the cuff around the limb using a motor with a defined set-point tensioning force. DE 198 59 392 A1 discloses a tensioning device for the cuff of a blood pressure measurement device in which the tensioning force is automatically limited to a predetermined set-point tensioning force. An electric motor is used to drive two winding reels onto which the ends of the cuff are wound, and a sensor is used to determine and control the force with which the respective cuff portions are wound on and consequently with which the cuff is tensioned around the wrist. However, this known tensioning device for cuffs of blood pressure measurement devices is relatively expensive and requires its own sensor system in order to obtain the desired tensioning force. In addition, the cuff is awkward to apply and remove, because on each occasion the cuff has to be wound or unwound using the adjustment motor.
Further blood pressure measurement devices according to the prior art are already known from DE 34 26 183 A, GB 2 348 134 A, DE 35 33 513 A, U.S. Pat. No. 4,206,765 A, EP 0 744 155 A, WO 01/50952 A, US 2002/103440 A1, GB 862 875 A and U.S. Pat. No. 5,660,182 A. According to the prior art, in order to apply the cuff in the known blood pressure measurement devices, a loop is formed which is large enough to accommodate the limb to be received in it and which is then tightened. This procedure has proven awkward.
The object of the present invention is therefore to make available an improved blood pressure measurement device of the type mentioned at the outset, which avoids the disadvantages of the prior art and advantageously develops the latter. The aim is to ensure, preferably by simple means, that the cuff is tightened around the limb in a reproducible manner with a predetermined force, and that it is easy to apply and remove the cuff.